全文获取类型
收费全文 | 271篇 |
免费 | 4篇 |
专业分类
化学 | 80篇 |
晶体学 | 6篇 |
力学 | 16篇 |
数学 | 63篇 |
物理学 | 110篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 11篇 |
2012年 | 5篇 |
2011年 | 15篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 15篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 14篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1990年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
31.
E. I. Timoshenko 《Algebra and Logic》2006,45(4):254-260
It is proved that test rank of a free solvable non-Abelian group of finite rank is 1 less than the rank of that group. This
gives the answer to Question 14.88 posed in the Kourovka Notebook by Fine and Shpilrain, asking whether or not a free solvable
group of rank 2 and solvability index n ≥ 3 has test elements.
Supported by RFBR grant No. 05-01-00292.
__________
Translated from Algebra i Logika, Vol. 45, No. 4, pp. 447–457, July–August, 2006. 相似文献
32.
We study the conformations of isolated trifunctional ampholytic dendrimers in solutions. For the previously homo-dendrimer case studied in the literature, we discuss the issues of density profiles, the existence of a cavity, backfolding, bond stretching and scaling laws for the dendrimer size across the good-to-poor solvent transition. We then consider the effect of introducing monomer charges in the outermost generation opposite to those in the interior generations in an electrically neutral overall ampholytic co-dendrimer. 相似文献
33.
E. I. Timoshenko 《Algebra and Logic》2006,45(1):67-74
For a factor group with respect to periodic part of a group of the form F/[R′, F], an embedding in the matrix group is defined.
The criteria for a matrix to belong to an image of this group and for elements to be conjugate are specified. Some statements
having a direct bearing on groups of the form in question are proved. Application of the results obtained allows us to refine
the answer in [7] to a question by O. Chapuis concerning the universal classification of ∀-free soluble groups with two generators.
Supported by RFBR grant No. 02-01-00293 and by FP “Universities of Russia” grant No. UR.04.01.227.
__________
Translated from Algebra i Logika, Vol. 45, No. 1, pp. 114–125, January–February, 2006. 相似文献
34.
35.
S. P. Timoshenko 《International Applied Mechanics》1971,7(10):1175-1176
36.
Dr. Gleb I. Tselikov Prof. Dr. Victor Yu Timoshenko Prof. Dr. Leonid A. Golovan Dr. Jürgen Plenge Alina M. Shatalova Georgiy A. Shandryuk Irina Yu Kutergina Alexey S. Merekalov Prof. Dr. Eckart Rühl Prof. Dr. Raisa V. Talroze 《Chemphyschem》2015,16(5):1071-1078
The photoluminescence (PL) of CdSe quantum dots (QDs) that form stable nanocomposites with polymer liquid crystals (LCs) as smectic C hydrogen‐bonded homopolymers from a family of poly[4‐(n‐acryloyloxyalkyloxy)benzoic acids] is reported. The matrix that results from the combination of these units with methoxyphenyl benzoate and cholesterol‐containing units has a cholesteric structure. The exciton PL band of QDs in the smectic matrix is redshifted with respect to QDs in solution, whereas a blueshift is observed with the cholesteric matrix. The PL lifetimes and quantum yield in cholesteric nanocomposites are higher than those in smectic ones. This is interpreted in terms of a higher order of the smectic matrix in comparison to the cholesteric one. CdSe QDs in the ordered smectic matrix demonstrate a splitting of the exciton PL band and an enhancement of the photoinduced differential transmission. These results reveal the effects of the structure of polymer LC matrices on the optical properties of embedded QDs, which offer new possibilities for photonic applications of QD–LC polymer nanocomposites. 相似文献
37.
I. S. Belotserkovets V. I. Timoshenko 《Journal of Applied Mechanics and Technical Physics》1984,25(1):69-73
Blowing at bluff body base was considered under different conditions and for small amount of blowing this problem was solved using dividing streamline model [1]. The effect of supersonic blowing on the flow characteristics of the external supersonic stream was studied in [2–4]. The procedure and results of the solution to the problem of subsonic blowing of a homogeneous fluid at the base of a body in supersonic flow are discussed in this paper. Analysis of experimental results (see, e.g., [5]) shows that within a certain range of blowing rate the pressure distribution along the viscous region differs very little from the pressure in the free stream ahead of the base section. In this range the flow in the blown subsonic jet and in the mixing zones can be described approximately by slender channel flow. This approximation is used in the computation of nozzle flows with smooth wall inclination [6, 7]. On the other hand, boundary layer equations are used to compute separated stationary flows with developed recirculation regions [8] in order to describe the flow at the throat of the wake. The presence of blowing has significant effect on the flow structure in the base region. An increasing blowing rate reduces the size of the recirculation region [9] and increases base pressure. This leads to a widening of the flow region at the throat, usually described by boundary-layer approximations. At a certain blowing rate the recirculation region completely disappears which makes it possible to use boundary-layer equations to describe the flow in the entire viscous region in the immediate neighborhood of the base section.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 76–81, January–February, 1984. 相似文献
38.
We study the first-order definable, Diophantine, and algebraic subsets in the set of all ordered sets generating a group or generating a group as a normal subgroup for some relatively free solvable groups. 相似文献
39.
L. A. Golovan’ A. A. Goncharov V. Yu. Timoshenko A. P. Shkurinov P. K. Kashkarov N. I. Koroteev 《JETP Letters》1998,68(10):770-774
Efficient visible-range photoluminescence with photon energy higher than the photon energy of the exciting radiation is observed
in nanostructures of porous silicon subjected to heat treatment in vacuum. The photoluminescence intensity is found to be
virtually identical for cw and femtosecond excitation by Ti:sapphire laser radiation with the same average power. The results
can be explained by a two-step cascade photoluminescence excitation process in which optical passivation of defects of the
dangling silicon bond type occurs.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 10, 732–736 (25 November 1998) 相似文献
40.
Yu. V. Chizhov M. M. Timoshenko G. S. Medynskii V. N. Baidin M. E. Akopyan N. I. Vasyukova Yu. S. Nekrasov 《Russian Chemical Bulletin》1985,34(6):1306-1308
Conclusions A study of the photoelectron spectra of benzenechromium tricarbonyl derivatives indicates the virtually complete loss of conjugation between the -aromatic system and the substituent of the coordinated ligand.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1425–1427, June, 1985.The authors express their gratitude to N. K. Baranetskaya and V. I. Losilkina for providing samples of the benzenechromium tricarbonyl derivatives studied. 相似文献